Bosch Series 4 WTH85226GB Review: 46p a Load, but Allow 3h25m
Bosch has discontinued the WTH85223GB that many people still search for. Its current 8 kg Series 4 heat pump dryer is the WTH85226GB, so that is the one we review here. It is cheap to run and owners rate it highly. The catch is time: a full cotton load takes nearly three and a half hours.
Where the testers agree
We could not find a public, hands-on editorial test of this dryer. Which? lists it in its lab results, but the score is behind its paywall. That leaves two other kinds of evidence: thousands of buyer ratings at AO.com and John Lewis, and owners talking plainly about heat pump dryers in a Mumsnet thread. All three point the same way.
It is cheap to run. A full 8 kg cotton load uses 1.74 kWh. At the Ofgem cap from 1 October 2026 (26.32p per kWh), that is about 46p a load, or about 27p for a half load. Which? puts the annual cost at £56.20. Owners like it a lot: it scores 4.7/5 across 3,538 AO reviews and 4.6/5 from 105 at John Lewis. The things they keep praising are the AutoDry sensor, how quietly it runs and the easy-clean filter.
The complaint is always time. The retailers list a full cotton load at 205 minutes and a half load at 125. Every heat pump dryer is slower than the vented and condenser dryers people are replacing, and both the buyer reviews and Mumsnet say so plainly. If you dry large loads every day, plan your evenings around it.
Heat pump or condenser, in a line: both collect the water in a tank so you do not need a vent hose. A heat pump dryer then reuses its warm air instead of throwing the heat away, so it uses about half the electricity but takes longer.
The three reviews this summary is built from
- Which?Lab-tested in August 2026, but the score is paywalled. We use only the public figures, such as the £56.20 annual running cost.
- AO.com & John Lewis4.7/5 from 3,538 reviews and 4.6/5 from 105, on pages that sell it. AO appears to pool reviews from earlier models.
- MumsnetA 30-reply owners’ thread on whether heat pump dryers are any good. Covers the whole category, not just this model.
Before the review: which model you are buying
The WTH85223GB is discontinued. Bosch’s own page says “Product is no longer available”, and John Lewis lists it as no longer available online. It was followed by the WTH85225GB, which some shops still sell, and now by the WTH85226GB, which Bosch lists as in stock at £629. The three share the same 842 × 598 × 613 mm body and 8 kg drum, but the figures differ. The WTH85225GB’s official fiche gives 1.87 kWh a load and 65 dB, while the WTH85226GB is listed at 1.74 kWh and 62 dB. If a listing just says “Bosch Series 4 8 kg heat pump”, check the model code before you pay.
Specification at a glance
| Spec | Figure | Confidence |
|---|---|---|
| Type | Freestanding heat pump (condenser) tumble dryer, 8 kg | Bosch |
| Energy rating | Sources disagree: A++ at Currys, AO, John Lewis and Marks Electrical. Bosch’s own spec table reads “Energy efficiency class D from D to A+++” | We think the Bosch line is a page error, but we have not been able to confirm that |
| Energy per load | 1.74 kWh full load · 1.02 kWh half load (cotton) | Currys; AO and Marks Electrical give the same full-load figure |
| Running cost per load | About 46p full · 27p half | Our sums at the Ofgem cap of 26.32p/kWh (1 Oct to 31 Dec 2026, Direct Debit) |
| Annual consumption | 216 kWh (AO, John Lewis, Marks Electrical) or 220 kWh (Currys) | About £57 to £58 a year at the cap; Which? says £56.20 |
| Cycle time | 205 min full load · 125 min half load (cotton). AO lists 159 min, which looks like a weighted average | Currys; Super Quick 40 for small loads |
| Noise | 62 dB (Bosch, Currys) or 63 dB (John Lewis, Marks Electrical) | Bosch’s figure is “62 dB(A) re 1 pW” |
| Condensation efficiency | Class B (Marks Electrical) or Class C (Currys) | Not on Bosch’s page; the WTH85225GB fiche says B, 83% |
| Drum volume | 112 litres | Marks Electrical only |
| Dimensions | 842 × 598 × 613 mm (H × W × D). John Lewis gives 648 mm deep and says to allow 850 × 600 × 648 mm | Bosch, Currys, AO, Marks. The 648 mm figure probably includes the door |
| Weight | 48.5 kg | John Lewis only |
| Drainage | Water tank, plus a drain kit for plumbing it in | Bosch, John Lewis |
| Warranty | 5 years if bought between 1 April 2026 and 31 March 2027 and registered within 3 months. John Lewis lists 2 years; AO lists 2, rising to 5 if you register within 90 days | Bosch’s terms; register on the day it arrives |
| Price | £629 at Bosch, John Lewis and Marks Electrical; £549 at Currys (was £629) | All checked 5 October 2026 |
Will it stack on the Bosch Series 4 washing machine?
We reviewed the Bosch Series 4 WAN28282GB washing machine. It is 848 mm high, 598 mm wide and 550 mm deep. This dryer is 598 mm wide too, so the two match side to side. Stacked, they come to about 1.69 m high before you add the stacking kit. The dryer is 63 mm deeper than the washer, so it will stick out a little at the front or back.
Currys lists the dryer as stackable. Bosch’s stacking kit, the WZ27410, is described as fitting a dryer on top of a full-size washing machine “depth >55cm”, and Bosch says to check that the kit is compatible with your dryer on the dryer’s product page. The WAN28282GB is exactly 55 cm deep, which is right on that limit. We could not find the WZ27410 listed for this model. Ask the seller to confirm the right kit before you order, and never stack the two without one.
Which?
Who they are: Which? is a not-for-profit consumer charity funded mainly by member subscriptions; it takes no advertising or sponsorship, buys almost every product it tests and runs the same lab tests across each category, so its results carry the most weight here.
Which? is the only independent body we found that has tested this exact model. The score, Best Buy status, measured drying times and noise rating are all behind its subscription, so we cannot tell you how it did. Treat this section as a pointer, not an endorsement. If you already subscribe, the result is worth checking before you buy.
The page does show some figures publicly: an A++ energy label, a 3.5 kg capacity on the synthetics programme, and an annual energy cost of £56.20. That matches our own sum closely: 216 kWh at 26.32p comes to about £56.85. Which? also lists the AEG TR818P4B (£559) and the LG RHX1009NWK (£498.98) as alternatives. Those are worth comparing if the drying time puts you off.
Watch: Bosch WTH85226GB Tumble Dryer
The only video we found for the current WTH85226GB. We confirmed it from two search listings, not by watching it.
Watch on YouTube ↗ Independent YouTube video, not made by or for Shopbam.AO.com and John Lewis
Who they are: AO gathers customer feedback through automated Trustpilot invitations; John Lewis’ ratings are moderated by PowerReviews, include labelled free-product reviews and enter each reviewer in a £100 prize draw. Both are buyer experience of delivery and use, not testing.
These ratings are hosted by shops that sell the dryer, so take them for what they are. AO shows exactly 3,538 reviews on both its WTH85226GB and WTH85225GB pages. That suggests AO combines reviews from earlier versions of the same dryer, so the large number is really for the Series 4 8 kg family rather than this model alone. The 105 reviews at John Lewis are fewer but more likely to be about this model.
Owners keep coming back to the same few things: the AutoDry sensor stopping when clothes are dry, how quiet it is (one review says it “won’t drown out” conversation in a kitchen), and the Super Quick 40 cycle for small urgent loads. AO’s page for the discontinued WTH85223GB shows its comments in full and backs this up. One buyer says it “dries towels quicker than my old condenser dryer”, and two say the filter is much easier to clean. The single negative review is the useful one. That buyer said it “takes considerably longer” and that clothes were not completely dry even on the sensor programme, so they had to run it again. That is the usual heat pump trade-off, and it is made worse by overloading the drum.
Watch: Bosch Series 4 Heat Pump Condenser Tumble Dryer WTH85225GB
Covers the previous WTH85225GB, which has the same body, drum and controls. The energy and noise figures differ slightly.
Watch on YouTube ↗ Independent YouTube video, not made by or for Shopbam.Mumsnet
Who they are: Mumsnet Talk is the site’s open discussion forum, where parents post their own experience of products; posts are unverified owner opinion, so the value lies in patterns repeated across many threads rather than in any single post.
This thread is not about this model specifically. It is useful because it is the kind of frank owner conversation that retailer pages filter out. The time penalty is real but smaller than people fear. One owner estimates “maybe half hour on a big full load” longer than their old dryer, while another’s record was eight hours for a mixed load. Several owners say heat pump dryers are kinder to clothes because they run cooler, and that they are quieter. One owner calls emptying the water and clearing the fluff after every load “hardly onerous”.
Two warnings are worth knowing before you buy. Heat pump dryers only work properly within a set temperature range, so one in a freezing garage or outbuilding may never dry a load. And on reliability, one poster’s Bosch heat pump dryer “lasted 10 days”, while another’s Bosch 9 kg had been “very reliable” after two years of heavy use. That is why you should register for the five-year warranty.
Watch: Bosch WTH85225GB 8 Kg Heat Pump Dryer
A second clip of the previous model. Useful for seeing the filter and water tank that owners talk about emptying after every load.
Watch on YouTube ↗ Independent YouTube video, not made by or for Shopbam.The good and the bad
What owners praise
- About 46p a full load and about £57 a year at the October 2026 cap.
- 4.7/5 across 3,538 AO reviews and 4.6/5 from 105 at John Lewis.
- The AutoDry sensor stops the cycle when the load is dry, rather than running for a fixed time.
- Quiet for a dryer at 62 to 63 dB, with anti-vibration side panels.
- No vent hose needed, and a drain kit is included so you can plumb out the water.
- Five years’ warranty if you register within three months.
What owners grumble about
- 205 minutes for a full cotton load, and longer if you overload it.
- You have to clear the fluff filter and empty the water tank after every load unless it is plumbed in.
- No self-cleaning condenser, so the condenser filter needs regular rinsing.
- Will struggle in a cold garage or outbuilding.
- Only 2 years’ cover unless you register, and some retailers advertise only the 2 years.
- The energy class, noise and condensation figures disagree between sources.
Who it suits
Buy it if you dry most of your washing at home, you want running costs well under half those of a vented dryer, and you can start a load and leave it. It suits a house with a Bosch washer already, as long as the stacking kit is confirmed. At Currys’ £549 it is reasonable value for a well-reviewed 8 kg heat pump dryer from a major brand.
Not the one if speed matters more than running cost, if the dryer will live somewhere unheated, or if you want a self-cleaning condenser. If you are replacing a WTH85223GB and just want the same again, this is the closest match Bosch currently sells.
What we were unable to verify
- Which?’s score and measured results. The test exists but is paywalled, and no other UK title has published a hands-on test that we could find.
- The energy class. Retailers say A++. Bosch’s own spec table says “D from D to A+++”. We could not find an official product fiche for the WTH85226GB to settle it.
- Noise, condensation class and annual kWh. 62 or 63 dB, Class B or C, and 216 or 220 kWh, depending on who you read. We have printed both figures each time.
- The stacking kit. We were unable to confirm which Bosch kit is listed for this model, or whether the WZ27410 suits a washer exactly 55 cm deep such as the WAN28282GB.
- Drum volume (112 L) and weight (48.5 kg) each come from a single retailer.
- The videos. We confirmed all three from two separately worded search listings, not by opening them, and the listings did not name the channels. Two of them show the previous WTH85225GB.
- AO’s review count appears to combine reviews from earlier versions of this dryer, so it is not a sample of WTH85226GB owners alone.
- The Mumsnet thread is from 2020 and covers heat pump dryers in general, not this model.
Sources last checked 5 October 2026. The running costs use the Ofgem cap for 1 October to 31 December 2026; work them out again when the cap changes in January.